1. Field of the Invention
The present invention relates to a protective sheath assembly for use with endoscopes, sigmoidoscopes, and other surgical illuminating devices. The sheath is disposable and can be discarded after each use of the endoscope or similar surgical illuminating instrument.
2. Description of Related Art
Endoscopes are generally used for observing inside bodily cavities through an illuminating object. One such endoscope is shown in U.S. Pat. No. 3,581,738 to Moore. The device disclosed therein comprises an elongated tubular element which is to be received in a bodily cavity. The tubular element contains optical fibers for transmitting light between the inside of the the bodily cavity and an eyepiece at the viewing end of the endoscope. As endoscopes are used for examining bodily cavities, it is considered necessary to sterilize these devices after each use.
One way to avoid having to sterilize the endoscope is to provide a sheath which protects the endoscope. A sterile sheath for a surgical illuminator is disclosed in U.S. Pat. No. 3,794,091 to Ersek et al. The sheath taught by Ersek et al comprises a tubular portion terminating in a pointed transparent tip. A severe drawback of the Ersek et al device is that it does not permit any communication at all between the cavity wall and the endoscope. Thus, it is not possible to perform biopsy functions and the like with an endoscope having such a sheath. Further, the pointed tip is not conducive to spray cleaning and similar operations which improve the visability of the endoscope while in use.
U.S. Pat. No. 3,417,746 to Moore et al discloses a disposable endoscope. Since the endoscope is used only once there is no need to sterilize it. Having to provide a new endoscope with each use, however, nonetheless incurs large costs.
U.S. Pat. No. 4,195,624 to Douglas discloses a tubular sheath to facilitate insertion of an endoscope. It is similar to the Ersek et al device, in that the sheath does not permit communication between a cavity and the endoscope, nor does it provide an endpiece which can be easily cleaned during use.
U.S. Pat. No. 4,201,199 to Smith discloses a glass tube having a bulbous end structure which fits over the shaft of an endoscope. The glass tubing is integrally formed as one unitary piece, with the bulbous end fitting over the terminal point of the endoscope. The end piece cannot be spray cleaned while in use, and the device does not permit communication between the endoscope and cavity in any manner.
As noted, none of the devices just described permits communication, i.e., the transfer of fluid or material between the endoscope and the body cavity being inspected. It is often desirable, however, that such communication be permitted. For example, the endoscope operator may wish to insufflate the cavity with air or some other gas, or irrigate it with water or another liquid. The operator may also or alternatively wish to remove material from the cavity by suction or forceps carried by the endoscope. The devices just discussed, however, have no provision for accomplishing these tasks, which of course makes them unsuitable when it is desired that these tasks be performed.